import com.mysql.cj.jdbc.MysqlDataSource;

import javax.sql.DataSource;
import java.sql.*;
import java.text.MessageFormat;
import java.util.Scanner;

public class test_DataSource {
    private static final String URL = "jdbc:mysql://127.0.0.1:3306/mysql_practice?characterEncoding=utf8&allowPublicKeyRetrieval=true&useSSL=false";
    private static final String USER = "root";
    private static final String PASSWORD = "Langwang0823*";
    public static void main(String[] args) {
        // 定义MySQL数据源对象
        MysqlDataSource mysqlDataSource = new MysqlDataSource();
        // 设置数据库连接串
        mysqlDataSource.setURL(URL);
        // 用户名
        mysqlDataSource.setUser(USER);
        // 密码
        mysqlDataSource.setPassword(PASSWORD);

        // 定义JDBC的数据源对象
        DataSource dataSource = mysqlDataSource;
        // 定义连接对象
        Connection connection = null;
        // 定义预处理SQL执行对象
        PreparedStatement statement = null;
        // 定义结果集对象
        ResultSet resultSet = null;

        try {
            // 通过数据源获取数据库连接
            connection = dataSource.getConnection();
            // 获取预处理的SQL执行对象
            // 定义要执行的SQL
            String sql = "select student_id, sn, name, mail, class_id from student where name = ?";
            statement = connection.prepareStatement(sql);
            // 接受用户的输入
            System.out.println("输入要查询的学生姓名：");
            Scanner scanner = new Scanner(System.in);
            String name = scanner.next();
            // 用真实值替换占位符
            statement.setString(1,name);
            // 执行SQL，获得结果集
            resultSet = statement.executeQuery();
            // 遍历结果集，获取数据
            while(resultSet.next()){
                long stuId = resultSet.getLong(1);
                String stuSn = resultSet.getString(2);
                String stuName = resultSet.getString(3);
                String stuMail = resultSet.getString(4);
                long classId = resultSet.getLong(5);
                System.out.println(MessageFormat.format("学生编号={0}, 学号={1}, 学生姓名={2}, 邮箱={3}, 班级编号={4}", stuId, stuSn,
                        stuName, stuMail, classId));
            }
        }catch (SQLException e){
            e.printStackTrace();
        } finally{
            //依次释放资源，关闭连接
            if(resultSet != null){
                try{
                    resultSet.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }
            if(statement != null){
                try{
                    statement.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }
            if(connection != null){
                try{
                    connection.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
            }
        }
    }
}
